You need to drive your 24’ cabin cruiser over a scale. I’ve had a lot of boats and I find it HIGHLY unlikely that any 24’ cabin cruiser on a trailer scales that light (4000 pounds).
My last 22’ cuddy cabin weighed 6000 on the trailer.
Campers that hang past the truck bed a bit aren’t a problem. Often boat trailers have enough tongue to still hitch right up. If they don’t, just use a hitch extension.
I tow a 26 foot cabin cruiser behind a dually pickup with an 11.5 foot camper, that hangs about 4 feet behind the truck.
Death wobble is worn out front track bars or other front end parts. If your truck is in good shape you won’t have it, and carrying a camper and towing your boat don’t cause more of it.
GM trucks don’t have it because they haven’t had straight axles in front since ‘87, ‘91 on the crew cabs.
The older diesels were loud. The newer ones are as quiet as a gas truck. Fuel price is higher but they get better mileage. Both of your reasons for not wanting a diesel are mistaken.
However, they’re expensive to buy and if you don’t drive a whole lot they don’t really pay for themselves. They make driving effortless with a camper and trailer with all their torque though.
You want a dually. It’s just gonna drive way more solid and confidently with the camper and.boat, and it isn’t any wider than the camper and boat already are.